Resistor values are measured in Ohms (Ω), kΩ (103 Ohms) and MΩ (106 Ohms). Commonly on circuit diagrams, the is omitted and k, M or R (for) replaces the decimal point, eg 3R3, 47k and 2M2. Most resistors have a power rating of 0.25W but, if a greater value is specified, do use it.
Resistors are marked with coloured bands to represent their value. The last band, separated by a larger gap, represents the tolerance, usually silver (10%) or gold (5%). If there are four bands, the first two represent digits and the third is a multiplier (ie number of zeros); with five bands, the first three are digits and the fourth is the multiplier. Black, brown, red, orange, yellow, green, blue, violet, grey and white represent 0-9 so red,…